Mou Weihua

A navigation signal simulator based on LXI

With the development of testing bus technology, PXI/VXI bus is implemented in navigation signal simulator. The automatic test software mostly communicates with the simulator by using direct I/O. Due to a lack of uniform standards, its not convenient for function upgrading and extension. A navigation signal simulator solution based on LXI(LAN eXtensions for Instrumentation) bus is proposed. Through the analysis of technique features of LXI bus standard, the hardware architecture of navigation signal simulator is designed. Meanwhile, the implementation of VXI-11-based remote control is mainly discussed. The simulator is controlled by driver interface in line with IVI (Interchangeable Virtual Instrumentation) specification to unify software programming interfaces of different simulators, so ATS (Automatic Test System) only needs to change the simulator driver after simulator upgrading or replacement which can greatly improve the reusability of automatic test software.

Direct acquisition method of long PN-code based on the GPU

In order to solve the acquisition problem of long PN-code spread spectrum signals, the partly correlation code phase-space acquisition model and implementation method of the FFT are analyzed. In order to segment data processing tasks and make full use of GPU to speed up FFT, a partly overlapped segmentation acquisition method of long PN-code is researched. Implementations of a direct global searching method and a partly overlapped segmentation searching method based on the GPU are then proposed, which parallel search for code phase using the FFT method, and accelerate FFT using the GPU. Simulation results indicate that, compared to a CPU implementation method, the search speed of the direct acquisition method of long PN-code based on the GPU is improved significantly.